jump.dev redirects for MathOptInterface docs

[mlubin]

The directory and link structure are copied over from the gh-pages branch of MathOptInterface. All .html files are replaced with redirects. All other files like js are copied without change (not sure if this is needed, but seems to be safe).

I have a script to generate these PRs for any repos with docs that we want to move from JuliaOpt to JuMP-dev.

[blegat]

Shouldn't this be merged into gh-pages so that the juliaopt server is updates one last time and then we move the repo to the JuMP-dev org ?

[mlubin]

Hmm, I've been assuming that when the repository is transferred, https://juliaopt.org/MathOptInterface.jl will disappear, so these files will replace that. Maybe the stale files would be left instead, I'm not sure.

[mlubin]

I tested this out and it seems to work as I expected. I created juliaopt/migration-test, moved it to the jump-dev org. The github pages for migration-test disappeared from juliaopt.org after the move. I then pushed a replacement page to juliaopt.org: https://jump.dev/migration-test/ https://www.juliaopt.org/migration-test/

[blegat]

Looks good then, let's do it.